Mounting of combustion elements



Jan. 28,1964 e. WEISS 3,119,439

MOUNTING o1 COMBUSTION ELEMENTS Filed Sept. 17, 1959 INVENTOR.

Gerhurt Weiss BY ATTORNEYS United States Patent 3,119,439 MOUNTING. 0FCOMBUSTION ELEMENTS Gerhart Weiss, Mineola, N.Y., assignor to AmericanThermocatalytic Corporation, Mineola, N.Y., a corporation of New YorkFiled Sept. 17, 1959, Ser. No. 840,769 1 Claim. (Cl. 158-99) Thisinvention relates to the arrangement of combus-- tion elements and morespecifically, to a mounting which permits easy access to, andreplacement of, combustion elements with minimum handling and effect onthe structure of these elements and their connections to the variousparts and accessories of a complete heating system.

One of the objects of the invention is to mount a hollow, elongated,porous, tubular element at both ends thereof in such a manner as toinsure feeding of the fuel vapor to its interior, and carrying off ofthe exhaust gases emerging from its walls, while insuring. duringoperation safe support substantially independent from the rapidtemperature changes involved in start, operation and stoppage,respectively, of such combustion elements.

In accordance with preferred embodiments of the invention, there isprovided heating apparatus comprising a rigid cylindrical metal casing,as well as a cylindrical, porous, open-ended, fibrous, self-supportingtube highly resistant to heat and of smaller diameter than the casingand disposed therein axially thereof. The tube and the casing havedifferent temperature coeficients of expansion. A rigid end cap closesone end of the casing and is formed with an axially disposed inletopening. A flexible and resilient diaphragm is supported on the innerface of the end cap with the major portion of the flexible diaphragmspaced inwardly from the inner face of the end cap. The cap and thediaphragm are cooperatively shaped to form a hollow chamber.

The flexible diaphragm has an opening axially thereof, and a furthertube is fixed to the diaphragm and extends thereinto through the openingthereof. Said further tube extends frictionally into the bore of thefibrous tube a short distance. The flexible diaphragm is adapted to beflexed so as to permit radial movement of the fibrous tube and of thefurther tube. The end cap, the flexible diaphragm and the further tubeare cooperatively shaped and connected to define a through passagebetween the outer face of the end cap and the interior of the fibroustube for flow of an air-fuel gas mixture therethrough.

The other end of the fibrous tube is spaced from the other end of thecasing. The other end of the casing has an exhaust opening, and saidother end of said fibrous tube is plugged by plugging means oftemperature coefiicient of expansion substantially the same as that ofthe fibrous tube. The plugging means has spacer means extending radiallytherefrom beyond the periphery of the fibrous tube and formed withexhaust ports therethrough.

It will be apparent from the foregoing that the structure in accordancewith this invention may be readily assembled and at the same timerequires the desired flexible mounting for the fibrous combustion tube.

Other objects of the invention will become apparent from the followingdescription in conjunction with the annexed drawing, in which preferredembodiments of the invention are disclosed:

FIG. 1 is a perspective view of the combustion tube in accordance withthe invention, showing the flexible diaphragm on one end thereof and theplugging means on the other end thereof.

FIG. 2 is a perspective view of the complete assembly of the combustiontube of FIG. 1 with the outer casing and associated elements.

FIG. 3 is a vertical longitudinal section of the assembly shown in FIG.2..

FIG. 4 is an end view of the assembly of FIGS. 2 and 3, taken in thedirection looking toward the plugging means.

FIG. 5 is an end view of the assembly of FIGS. 2 and 3, looking towardthe opposite end from that; of FIG. 4.

FIG. 6 is a view corresponding to FIG. 4, but showing a secondembodiment of the plugging means- In FIGS. 1, 2 andv 3, a catalyticheater element such as shown at 1 and consisting, for example, ofcatalyticallyactive fibers sintered into the form of a hollow tube issupported at its inlet end on a. high heatvresistant, metallic sleeve orinner fejeder tube 2. (FIG. 3) which. in turn is supported on a. thin,preferably flexible and; heatresisting or metallic diaphragm or sheet.3,, consistingfor example of stainless steel foil of. the shapeapproximately indicated in FIGS. 1 and 3-.

Sleeve 2 is provided with an outer projection, 4 serving as a stop forthe mountingv of heater tube 1 while another inner projection 5 forms astop for the mounting of foil 3 supporting feeder tube 2 and heatertube 1. The central supporting surface of foil 3 has an axial openingintov which tube 2 extends.

Foil 3', at its central supporting surface for feeder tube 2, is weldedor brazed to feeder tube 2 while at its periphery, it is bent out of itsplane, and supported; or clamped at. 7 between section 12 of outer tube8 and the end wall of closure cap 9. Said tube 8 is rigid andcylindrical and serves as the outer casingv of the as.- sembly. Tube 8together with tube 1 and closure cap 9 forms a channel for the hotexhaust gases passing in the direction 10 after having entered in theform of fuel vapors through inner feeder tube 2 in the direction ofarrow 11.

Closure cap 9 is attached upon section 12 of outer tube 8 and has anopening 9a supporting an inlet tube 13 permitting access of the fuelvapors in direct-ion 11.

lFoil 3 is also shaped bulging :out at its central portion in the mannerindicated in FIGS. 1 and 3 to provide a space or hollow chamber 3bbetween the supporting or central portion of foil 3 and the inner end ofinlet tube 13 thereby increasing flexibility as well as expansibilityand compressibility in all directions of the heater assembly undercontrol of widely varying temperatures such as occur in combustionheater installations.

In order to facilitate manufacture and assembly at the front end ofheater element 1, the surrounding front section 12 of outer tube 8 ismade of a separate piece of stainless steel or other heat resistantmaterial. If necessary outer tube 8 including section 12 can be made ofone piece of stainless steel.

Heater tube 1 at its rear end is shown to be supported on a plug element14, consisting preferably of heat insulating material and provided atits periphery with radial extensions or ribs 15 providing exhaust portstherebetween and permitting passage therebetween of the exhaust gases inthe direction of arrow 10, while supporting heater tube 1 spaced insideouter tube 8. The spaces 14a between the spacer means or radialextensions 15, and also bounded by the central part of the plug element14 and the tube or casing 18, accordingly serve as exhaust ports forflow of the exhaust gases out of the end of the casing.

Instead of making the supporting plug element of spider shape as shownin FIGS. 1, 3 and 4 at 14, 15, it maybe made to consist of a disc 16provided with a number of openings or exhaust ports 17, adapted topermit passage of exhaust gases while suppressing passage of flame'therethrough (see FIG. 6).

All these arrangements facilitate removal and/ or replacement of heatertube 1 as a structural unit.

Cover 9 is removable by turning. A bayonet type closure schematicallyindicated at 18, serves to close extension 12 of the outer tube 8 in agas-tight manner at its front end. This closure is effected, preferablyas illustrated in FIG. 3, by pressing the outer feeder tube 13 (which isWelded, brazed or otherwise attached) to cover 9 through gaskets 20 and21 against the outer peripheral portion 7 of supporting disc ordiaphragm 3, which in turn is thus clamped to the front edge of section12 of outer tube 8.

The bayonet closure may be replaced by a thread without departing fromthe scope of this disclosure.

The front section 12 of outer casing 8 has a peripheral opening for theinsertion of an exciter or igniter element such as acatalytically-active platinum wire, or of a thermostat or any othercontrol element or elements, schematically indicated in FIG. 3 at 22.

The invention is not limited to the type, shape, form, or material ofthe supporting elements shown or described nor to the particular shapeof the heater and heat carrying tubes, accessories or parts nor to theparticular arrangement of the supporting and control mechanismsdisclosed but may be applied in any form or manner whatsoever withoutdeparting from the scope of this disclosure.

What is claimed is:

Heating apparatus comprising a rigid cylindrical metal casing, acylindrical, porous, open-ended, fibrous, selfsupporting tube highlyresistant to heat and of smaller diameter than said casing and disposedtherein co-axially thereof, said tube and said casing having differenttemperature coefiicients of expansion, a rigid end cap closing one endof said casing and being formed with an axially disposed inlet opening,a flexible and resilient diaphragm, means supporting said flexiblediaphragm on the inner face of said end cap with the major portion ofsaid flexible diaphragm spaced inwardly from said inner face of said endcap, said cap and diaphragm being cooperatively shaped to form a hollowchamber, said flexible diaphragm having an opening axially thereof, afurther tube fixed to said diaphragm and extending thereinto throughsaid opening thereof, said further tube extending frictionally into thebore of said fibrous tube a short distance, said flexible diaphragmbeing adapted to be flexed so as to permit radial movement of saidfibrous and further tubes, said end cap, said flexible diaphragm andsaid further tube being cooperatively shaped and connected to define athrough passage between the outer face of said end cap and the interiorof said fibrous tube for flow of an airfuel gas mixture therethrough,the other end of said fibrous tube being spaced from the other end ofsaid casing, said other end of said casing having an exhaust opening,and plugging means of temperature coefficient of expansion substantiallythe same as that of said fibrous tube plugging said other end of saidfibrous tube, said plugging means having spacer means extending radiallytherefrom beyond the periphery of said fibrous tube and being formedwith exhaust ports therethrough.

References Cited in the file of this patent UNITED STATES PATENTS821,939 Harris May 29, 1906 1,213,470 Finlay Jan. 23, 1917 2,048,993Claffey et a1 July 28, 1936 2,253,920 Vaughn Aug. 26, 1941 2,336,879Mekler Dec. 14, 1943 2,821,510 Gottwald Jan, 28, 1958 FOREIGN PATENTS183,084 Austria Sept. 10, 1955 1,056,454 France Oct. 21, 1953

